Nonstressed antepartum heart rate monitoring: implications of decelerations after spontaneous contractions.

Fetal outcome in 98 patients with spontaneous antepartum late decelerations was studied by combining the data of two obstetric departments. Heart rate variability was used to classify the different patterns into two categories: terminal and decelerative. In 14 of the 47 pregnancies in which a terminal pattern was found, intrauterine death occurred within a week. Of the remaining 33 fetuses, 71% were acidemic at elective cesarean section (CS). In contrast, all of the 51 fetuses with a decelerative cardiotocogram (CTG) survived the antenatal period, and only two of 25 were acidemic at elective CS. Labor was induced in 20 patients with a decelerative CTG, and fetal distress occurred in 12, of whom 10 were eventually delivered by CS. All fetuses with a repetitive decelerative heart rate pattern antepartum developed distress in labor. In contrast, an isolated deceleration, on one occasion only, was not associated with distress during labor, except in growth-retarded fetuses. The clinical implications of these findings are discussed and the results are compared with those of oxytocin contraction stress tests.